Three drivers allegedly tested positive to drugs during a joint police and ACT Corrective Services operation targeting contraband at the Alexander Maconochie Centre on Saturday.

Between 1pm and 6pm, officers stopped and searched vehicles visiting the prison, conducted licence and registration checks, and intercepted vehicles attempting to avoid the operation.

Police issued four vehicle defect notices and six traffic infringement notices, while multiple items were seized for further examination. One visitor was also turned away for breaching prison visitation rules.

Police say the operation targeted the movement of contraband, including illicit drugs, mobile phones and other prohibited items, into the prison.

It was the third joint operation targeting contraband at the Alexander Maconochie Centre since November.

News all day, every day at CityNewsQBN.com.au.